Why is my answer truncated? Tell me why she became famous. - a statement, an imperative. Not a question. Show me why I need to do this. Tell me when I get to eat. . A standard construction, word-order in English to mean an imperative, a direction, a demand. . On this site, and sometimes in other places, but usually online, where grammar is often somewhat questionable, you will find this construction used. For example: How to express this in English? - With my upbringing, this is not a question, not correct: it's a fragment, incomplete. As above, it is part of a longer construction with an imperative meaning. . The reason? These are the accepted, considered "correct" rules used in English. How did I do in explaining?

Why did she become famous?

From my point of view, "did" must be used.

"Why she became famous" would be the normal way of expressing "Why did she become famous" in the past tense. The "did" in "Why did she became famous" is used when the speaker wants to emphasise the fact. In conclusion, the both sentences are correct.

OK, the site keeps truncating answers